It is known to provide an apparatus, such as an occupant restraint (e.g., seatbelt), inflatable vehicle occupant protection device (e.g., air bag), impact absorbing structure (e.g., padded or collapsible structures), or a combination thereof, for helping to protect an occupant of a vehicle. One particular apparatus is a head restraint positioned above or at the upper extent of a seat back of a vehicle seat. Head restraints may be adjustable in order to place the head restraint in a desired position relative to differently sized occupants of the vehicle seat. The head restraint may be effective to help protect the occupant of the vehicle seat upon the occurrence of an event for which occupant protection is desired, such as a vehicle impact (e.g., a rear impact). When such an event occurs, the head restraint helps protect the occupant by helping to absorb impacts with the head restraint and by helping to restrict or limit movement of the occupant's head and neck.